1. From two points on the ground and lying on a straight line through the foot of a pillar, the two angles of elevation of the top of the pillar are complementary to each other. If the distances of the two points from the foot of the pillar are 9 metres and 16 metres and the two points lie on the same side of the pillar, then the height of the pillar is

12 m

5 m

10 m

7 m

2. The sum of interior angles of a regular polygon is 1440°. The number of sides of the polygon is

8

10

12

6

3. The base of a right prism is a right-angled triangle whose sides are 5 cm, 12 cm, 13 cm. If the area of the total surface of the prism is 360 cm2, then its height (in cm) is

11

10

12

9

4. LCM of two numbers is 2079 and their HCF is 27. If one of the numbers is 189, the other number is

216

297

584

189

5. Three pipes A, B and C can fill a tank in 6 hours. After working together for 2 hours, C is closed and A and B fill the tank in 8 hours. The time (in hours) in which the tank can be filled by pipe C alone is

9

10

12

8